The present proposal continues work under "Quantitative Analysis of Judgment." The earlier studies on human information processing emphasized judgmental processes in detection, discrimination and recognition. The project will apply our previous work on perceptual and cognitive processes of judgment, and on formal models of structure, to models of complex natural systems such as reading, listening, or understanding. The range of studies include (1) basic processes of auditory perception, (2) the development of speech recognition in neonates and infants, (3) theoretical and experimental studies of auditory and visual information processing with special attention to reading and (4) the role of cognitive and perceptual systems in learning disorders. Our long-term goal is a complete theory of perceptual judgment. We seek to understand the ways in which the more primitive aspects of perception, such as patterning, selectivity, and the equivalence of some spatial and temporal sequences are integrated by perceptual and cognitive processes to form the final judgment.